The invention relates to a transporting apparatus for conveying carriers, according to the introductory part of claim 1.
Such a transporting apparatus is disclosed in German Offenlegungsschrift No. 17 56 438.
Such a transporting apparatus is used, for example, to convey workpieces from one production stage to the next, whereby the transporting apparatus must allow for a back-up of full or empty carrier as they arrive, which may come about due to the different speeds at which the workpieces are removed or loaded.
The known transporting apparatus exhibits a pair of parallel, mutually spaced continuous conveyor belts which run across deflection wheels. The carriers are each in frictional engagement with these belts in such a way that the conveyor belt can slide through in the case of a back-up.
Lifting apparatus, among other things, is necessary for conveying systems which make use of such transporting apparatus; the driving means is also elaborate. Furthermore, the number and weight of the carriers which can be moved by one transporting apparatus are limited due to the necessary frictional engagement.
These disadvantages are remedied by the subject-matter of German Pat. No. 25 22 299 by replacing the two conveyor belts by two continuous chains. These chains run in rigid guide tracks in two loops which are parallel to one another and each arranged on a vertical plane, those flanks of each chain which face one another protruding out of the guides. The carriers are attached to the protruding ends of the chains by means of resilient jaws.
Although the disadvantages stated above are remedied to a large extent by the latter transporting apparatus, this improved apparatus in turn involves considerable disadvantages, viz. great attrition, a high noise level imposed on the surroundings and in particular a complicated construction due to the chains themselves, the tension apparatus necessary therefor and the elaborate means for clamping the carriers. Furthermore, the overall length of the known transporting apparatus, as well as the number and carrying capacity of the carriers which can be moved thereby at the same time, are again limited, in particular because the jaws, which engage only with the flanks of the chains, tilt the chains in their guideways.